CXCL8 and infection: To delineate the mechanisms involved in Adh-mediated IL-8 release, we evaluated the activation of p38, JNK, and ERK by western blotting and found that although A. pleuropneumoniae infection can induce the activation of MAPK signaling, 5b WT infection can induce higher levels of phosphorylation of p38 and ERK than 5b ΔAdh infection at 30 and 60 min post-infection (Fig. 5A).